Hi, I've just released the first alpha of CrutziPlayer, a standalone player for NPAPI browser plugins (like libflashplayer.so)
It can be downloaded in source (Python) as a .deb on http://www.crutzi.info/crutziplayer

It's very unique, as it uses a new method to scale flash content fullscreen, using XComposite, XFixes and Cairo.
E.g. playing the game Samorost fullscreen is as easy as

crutziplayer -f http://amanita-design.net/samorost-1/main.swf

Please let know how it works for you. It's only been tested on Ubuntu 12.04 so far.